This invention represents an improvement in postage register printing systems, specifically those which print values on a sheet, tape or stamp, by means of print wheels housed in, and protruding from, a rotatable printing head. More specifically this invention represents an improvement in devices of the type in which at least one print wheel bank is automatically advanced a pre-set amount by means of the rotation of the printing head.
However, it will become clear as this invention is described, that the improvements recited herein are applicable to any printing system or device in which the printing dies are contained on a wheel or set of wheels which are rotated to set the value or values to be printed.
The improvements herein will be described with relation to the type of postage register printing systems which, in addition to printing the postage to be affixed to a given parcel, also print numbers to identify parcels on the same postage stamp of tape. As is generally well known in this field, modern postage printers are controlled electronically by micro-processing technology; however, the improvements herein are equally useful or applicable in mechanical or semi-mechanical mode.
Typical postage printing systems are disclosed in U.S. Pat. No. 2,829,591, showing a printer with a rotatable printing head containing print wheels; and U.S. Pat. Nos. 3,965,815 and 4,050,374, which show and describe various setting mechanisms for setting the print wheels in a postage meter, and thus fixing the postage amount to be printed. Electronic control systems for automatically carrying out the functions of a postage printing system have been designed, such as that disclosed in U.S. Pat. No. 3,978,457.
Two common types of postage value printers in use today are used by the U.S. Postal Service and by the United Parcel Service (UPS) respectively. In the Postal Service device, such as the Pitney-Bowes Model 5300, shown in U.S. Pat. No. 2,829,591, there are four print wheels in a postage print wheel bank which can provide a postage impression up to $99.99. Each print wheel provides a separate digit of this sum, and is settable from 0-9. Setting mechanisms include those disclosed in the foregoing patents. The actual print impression process by which the printing drum rotates to stamp a postage value on a substrate is described in said U.S. Pat. No. 2,829,591.
However, in the UPS device, in addition to the bank of postage print wheels, there is an additional bank of print wheels laterally spaced along the drum from the postage print wheel bank, for impressing a parcel identification number (PIN) near the postage amount on the postage stamp. The PIN information and accumulated postage are stored in the printer by known means, and in this manner, UPS can estimate the average postage normally used per parcel over a period of time, by dividing the accumulated postage by the total PIN count. Additionally, the PIN of course provides a number to identify and follow the parcel through the delivery process.
The PIN print wheel bank is typically automatically set, or advanced, by the rotation of the printing drum around a stationary cam attangement. Every rotation of the drum, which in these printers corresponds to one postage impression, produces a PIN increase of one by the interaction of the PIN print wheel bank with the stationary cam. By the positioning of the cam, the PIN counter may be advanced one unit either at the end of a drum rotation, so as to show the next PIN in advance of the next drum rotation, or at the start of or during drum rotation. If it is the latter, when the drum is in a rest position, the PIN print wheel bank will show the previous PIN. As will become clear hereafter, this is the PIN count mode desired in apparatus encompassing the present improvements.
Thus, it can be seen that one PIN is printed out sequentially every time the drum is rotated once to print postage or other information. It is in the latter instance that the problem arises which is solved by the inventive improvements described and claimed herein.
Ideally, the printer operator would like to have the PIN count correspond exactly to the number of parcels to which postage has been affixed over a given period of time, and to have one PIN identify, or be unique, to a given parcel. However, for example, when a parcel is sent "cash-on-delivery" (COD), the postage register must be activated twice: once, to print out a proper postage as usual, and again to stamp out an additional charged amount when the parcel is delivered (COD stamp). Obviously, since the printing drum is rotated twice in the case of a COD parcel, two consecutive PINS will be indicated on the two stamps of this one parcel. Clearly, the more COD parcels sent during a given period of time, the less the PIN count will correspond to the actual number of parcels posted. For record keeping purposes, it is desirable that one PIN be used per parcel, even if that parcel is sent COD with two stamps. In other words, for COD of similar situations, where multiple stamps must be affixed to one parcel, a given PIN should be repeatable for each stamp placed on a given parcel.